Phosphonic acid esters and process for their production



United States Patent Ofilice 3,29,Z? Patented Apr. 10, 1982 The present invention relates to and has as its objects new and useful phosphonic acid derivatives with especially insecticidal or more broadly pesticidal properties. Generally the new compounds of the present invention may be represented by the following formula ll CHFoH-P in which R stands for a lower alkyl radical up to 6 carbon atoms and R stands for substituted alkyl or possibly substituted aralkyl or aryl radicals. The preparation of the new compounds of this invention may be carried out by methods known in principle, but should be described in more detail in the following description. Ester chlorides of vinyl-phosphonic acids and vinylthionophosphonic acids can be converted into vinyl-phosphonic, vinyl-fluonophosphonic acid esters or vinylthionothiolphosphonic acid esters by known methods. In the case of vinyl-phosphonic acid esters it is possible to produce esters with various alkyl radicals. Esters of this kind have hitherto not been known in the liaterature, nor have vinyl-thionophosphonic acid esters been described in literature.

Various ways can be used for the production of the new compoundsclaimed according to the invention. It is thus possible to react, for example, viny1-(thiono)- phosphonic acid alkyl ester chlorides with optional alcohols, phenols or mercaptans. The following reaction scheme illustrates this reaction:

Vinyl-thionophosphonic acid alkyl ester chlorides may also be saponified with alkali metal hydroxide and then reacted with optional alkyl halides, arakyl halides or if desired, with aryl halides. This reaction is illustrated by the following reaction scheme.

Vinyl-thionothiolphosphonic acid esters can also be obtained e.g. via an alkali metal especially the potassium salt I, easily obtainable with potassium hydrogen sulfide, for example from vinyl-thionophosphonic acid alkyl ester chlorides, and subsequent alkylation:

S OH] (ll-R1 CH2=C11- K01 In the above reaction scheme R stands in each case for a preferred lower alkyl radical whilst R may stand for optionally substituted alkyl, aralkyl or ary-l radicals as described in the beginning of the description.

The compounds obtainable according to the invention as said above have the following general composition:

wherein R stands for lower alkyl radicals, preferably with 1-6 carbon atoms, and R stands for a substituted alkyl radical or an optionally substituted aralky l or aryl radical; R thus may stand for the following radicals, given as examples but not intended to limit the scope of this invention in any way: CH3SC2H5 The intermediate vinyl-phosphonic acid or vinyl-thiephosphonic acid ester chlorides are obtainable by a simple process discovered in the meantime. This process consists in reacting vinyl-phosphonic acid dihalides (chlorides) with about the stoichiometrical amount of alcohols in the presence of acid-binding agents especially of tertiary amines, or by reacting the corresponding vinyl-thionophosphonic acid dihalides (chlorides) with about stoichiometrical amounts of especially alkali metal alcoholates.

The new compounds obtainable according to the invention are intended to be used in the first place as plant protective agents or insecticides. They are preferably used in combination with suitable solid or liquid extenders or diluents. Suitable solid extenders are, for example, talc, chalk, bentonite or kieselguhr, or in the case of liquid agents, water, preferably in combination with suitable emulsifiers and an organic solubilizer such as, for example, dimethyl formamide or acetone.

As an example for the special utility of the inventive compounds the compounds of the following formulae O 02 (II) have been tested against aphids and spider mites. Aqueous solutions of the aforementioned compounds have been prepared by admixing them with the same amount of an auxiliary solvent (acetone). A commercial emulsifier (benzyl hydroxy diphenyl polyglycol ether) is added in an amount of 20% referred to active ingredient. This premixture then is diluted with water to th desired concentrations. The tests have been carried out as follows:

(a) Against aphids of the type Doralis fabae: heavily infested bean plants (Vicia faba) have been sprayed drip wet with solutions as prepared above. The eifect has been determined after 24 hours by counting the dead pests either on the surface of the soil or still remaining on the plants. The following results have been obtained:

Compound aqueous concentration killing rate (in percent active (in percent) ingredient/water) (I) 0.01 100 (II) 0.01 100 Compound aqueous concentration killing rate (in percent active (in percent) ingredient/water) The following examples are given for illustrating the present invention:

Example I O OC Hs 145 grams of vinyl-phosphonic acid dichloride (1 mol) (B.P. 44/ 1 mm. Hg) are dissolved in 1000 ml. of petrol ether. While stirring there is added at 10 to 20 C. a mixture of 101 grams of triethyl amine and 48 grams of anhydrous ethanol. Stirring is continued for 1 further hour, and the triethyl amine salt which has been formed is filtrated with suction. The remaining solution is freed from solvent by distillation and the residue is distilled under high vacuum, the vinyl-phosphonic acid ethyl ester chloride distilling at 1 mm. Hg/49 C. is obtained. The yield amounts to 75% of the theoretical.

Calculated for mol 155: P=20.1%; Pound: P=19.7%; Cl=23.2%.

Example 2 322 grams (2 mols) of vinyl-thionophosphonic acid dichloride (13.1. 46 C./1 mm. Hg) are dissolved in 1500 ml. of benzene whereupon While stirring there is added at 0 to C. a concentrated sodium ethylate solution containing 46 grams of sodium metal. Thereafter stirring is continued for further 10 minutes and the reaction mixture is poured into ice-water. The benzenic layer is separated, washed once with 100 ml. of water and then is dried over anhydrous sodium sulfate. After fractionated distillation there are obtained 232 grams of vinyl-thionophosphonic acid ethyl ester chloride (B.P. 48 C./l mm. Hg). The yield is 68% of the theoretical.

Calculated for mol 171: Cl=20.8%; S=l8.3%; P=18.1%. Found: Cl=20.7%; S=17.8%; P=17.9%.

4 Example 3 39 grams (0.25 mol) of vinyl phosphonic acid ethyl ester chloride (Bl 49 C./ l mm. Hg) is added dropwise with stirring at 3040 C. to 40 grams of p-nitrophenol sodium salt dissolved in 150 cc. of methyl ethyl ketone. Stirring is continued for an hour whereupon the reaction product is added to 300 cc. of ice water. The precipitated oil is taken up in 200 cc. of benzene and deacidified with a 4% solution of bicarbonate. After drying, the benzene solution is fractionated. 35 grams of the ester of HP. 119 C./0.0l mm. Hg is obtained. Yield 55% of the theoretical.

Solutions of 0.01% kill aphids 100% and spider mites 65%.

Example 4 O O C2115 li/ CHz=CH-P 39 grams (0.25 mol) of vinyl-phosphonic acid ethyl ester chloride are added dropwise with stirring at 30 C. to 45 grams of 3-methyl-4-methyirnercapto-phenol sodium salt dissolved in 200 cc. of methyl ethyl ketone. Heating is continued at 30 C. for an hour and the reaction product is then added to 300 cc. of ice-Water. The precipitated oil is taken up in 300 cc. of benzene, deaciditied with a solution of sodium bicarbonate and dried with sodium sulfate. Upon fractionating, 40 grams of the new ester of B.P. 112 C./0.0l mm. Hg are obtained. Yield 59% of the theoretical.

0.01% solutions kill aphids 100% and spider mites 40%.

Example 5 S 0C2H5 CH2=CH-P O-CHrCHg-SCgHg 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride (B.P. 48 C./1 mm. Hg) are added dropwise with stirring to 28 grams of fl-hydroxyethylthioethyl ether dissolved in 150 cc. of methyl ethyl ketone. 40 grams of finely powdered and dry potassium carbonate are added to the suspension and the mixture is heated to C. for 2 hours. The reaction mixture is then cooled to room temperature. The precipitated salt is fitered off with suction. The filtrate is added to 300 cc. of water. The precipitated oil is taken up in 400 cc. of chloroform, washed neutral with Water and dried over sodium sulfate. Upon fractionating, 32 grams of the new ester of B.P. 79 C./0.01 mm. Hg are obtained. Yield 53% of the theoretical.

0.01% solutions kill aphids and spider mites 60%.

Example 6 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are added dropwise with stirring to a solution of 36 grams of 4-chlorophenyl-mercaptan dissolved in a solution of sodium ethylate containing 1/4 mol of sodium. The temperature is kept at 20 C. during the dropping in and stirred for an hour after the dropwise addition. The reaction product is then added to 300 cc. of ice-water and worked up in usual manner. 34 grams of the new ester of B.P. 126 Yield 49% 6 grams (0.25 mol) of powdered sodium are suspended in 100 cc. of benzene. 60 grams of diethyl aminoethanol are added with stirring at 50 C. to the suspension. Heating is continued at 50 C. for an hour and 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are added dropwise with further stirring at 30 C. The mixture is stirred at 30 C. for a further hour, the reaction product is taken up in 200 cc. of benzene and the mixture is added to 300 cc. of ice-water. After conventional Working up, 40 grams of the new ester of B.P. 88 C./0.01 mm. Hg are obtained. Yield 64% of the theoretical.

Example 8 S 11 ll/ CH2=CHP 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are added dropwise with stirring at 20 C. to 41 grams of p-methylmercapto-phenol sodium salt dissolved in 200 cc. of methyl ethyl ketone. The mixture is stirred at 20 C. for a further hour and then worked up in usual manner. The resulting ester obtained as a water-insoluble oil is kept for a short time at a bath temperature of 70 C. and 1 mm. Hg pressure. 57 grams of the new ester are obtained in this manner. Yield 83% of the theoretical.

0.01% solutions kill aphids to 100% and spider mites to 90%.

Example 9 fi/OCJHE 0H3=CH-P Example 10 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are added with stirring at 60 C. to a solution of 56 grams of 3,4,6-tn'chlorophenol sodium salt in 100 cc. of methyl ethyl ketone. Heating is con tinued at 50-60 C. for 10 hours, the reaction product taken up in 300 cc. of benzene and the benzene solution is washed several times with water. The resulting crude product is kept at a bath temperature of 70 C. in a vacuum of 1 mm. Hg for a short time. In this manner, 60 grams of the new ester are obtained as a water-insoluble pale yellow oil. Yield 72% of the theoretical.

Example 11 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are added with stirring at 60 C. to a solution of 48 grams or" 2,4-dichlorophenol sodium salt in 100 cc. of methyl ethyl ketone. The mixture is stirred for a further 10 hours and then worked up in conventional manner. 54 grams of the new ester are obtained as a water-insoluble pale yellow oil. Yield 73% of the theoretical.

Example 12 O OC2H5 ll/ CHz=CH-P 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are heated with 30 grams of potassium hydroxide dissolved in 50 cc. of water with the addition of 20 cc. of anhydrous alcohol to C. for an hour. In this way the sodium salt of the following constitution is formed:

0 00211. ll/ e O Na SN a 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are added with stirring to a solution of 36 grams of potassium hydrogen sulfide in cc. of anhydrous alcohol. The mixture is heated to 40 C. for an hour and 28 grams of e-chloromethyl-thioethyl ether are then added with stirring. The whole is kept at 50 C. for a further hour and then Worked up in conventional manner. 37 grams of the new ester of B.P. 70 C./0.0l mm. Hg are thus obtained. Yield 61% of the theoretical 0.01% solutions kill aphids to 100% and spider mites to 40 Example 14 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are added with stirring to a solution of 36 grams of potassium hydrogen sulfide in 100 cc. of anhydrous alcohol. The mixture is heated to 40 C. for an hour and 32 grams of fl-chloroethyl-thioethyl other are then added with stirring at 80 C. Heating is continued at 80 C. for an hour and the mixture is worked up in conventional manner. 34 grams of the new ester of HP. 79 C./0.01 mm. Hg are obtained. Yield 53% of the theoretical.

Spider mites Example 15 8 002115 CH2=CHP 43 grams (0.25 mol) of vinyl-thionophosphonie acid ethyl ester chloride are added with stirring to 36 grams of potassium hydrogen sulfide in 100 cc. of anhydrous ethyl alcohol. The mixture is kept at 40 C. for 1 /2 hours and 52 grams of a-chloro-rnethyl-p-chlorophenylthioether are added. The reaction product is kept at 50 C. for a further 2 hours and then added to 300 cc. of ice-Water. The precipitated oil is taken up in 200 cc. of benzene and washed several times with water. After removing the solvent, a water-insoluble yellow oil is obtained which is kept for a short time at a bath temperature of 70 C. and a vacuum of 1 mm. Hg. 58 grams of the new ester are thus obtained. Yield 72% of the theoretical.

Example 16 In an analogous manner there are obtained from 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride, 36 grams of potassium hydrogen sulfide and 40 grams of a-chloromethyl-thiophenyl ether, 51 grams of the new ester. Yield 70% of the theoretical.

0.01% solutions kill aphids to 100% and spider mites to 75%.

Example 17 B O C2115 CHFCH-P C 2-C 2N (C 2 2 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are added with stirring at 40 C. to 36 grams of potassium hydrogen sulfide in 100 cc. of anhydrous alcohol. The mixture is warmed at 40 C. for an hour and 50 cc. of acetonitrile are then added. 35 grams of fi-chioroethyl-diethylamine are then added dropwise at 70 C. to the mixture. The mixture i heated to 80 C. for an hour, then cooled to room temperature and the reaction product is added to 300 cc. of ice-Water. The separated oil is taken up in 200 cc. of benzene and dried with sodium sulfate. Upon fractionating, 30 grams of the new ester of BB. 84 C./0.01 mm. Hg are obtained. Yield 45% of the theoretical.

0.001% solutions kill aphids to 40% and spider mites to 80%.

Example 18 IS 0 C2115 0H OH-P 0 SCHa CH 43 grams (0.25 mol) of vinyl-thionophosphonic acid ethyl ester chloride are added with stirring at 30 C. to 45 grams of 3-methyl-4-methylmercapto-phenol sodium saltester of Bi. C./0.0l Hg are obtained. Yield 69% ot' the theoretical.

Example 19 S-OH-CHZ-SCZH5 CIIa 52 grams (0.25 mol) of vinyl-thionophosphonic acid- O-ethyl ester-thiolic acid potassium salt (Ml 186 C.) are dissolved in cc. of acetonitrile. 35 grams of 2- chloro-isopropyl-thioethyl ether (Bi 56 C./ 13 mm. Hg) are added thereto with stirring at 80 C. The reaction product is heated at 80 C. for an hour, diluted with 300 cc. of benzene and then added to 200 cc. of ice- Water. After conventional working up there are obtained 40 grams of the new ester of 13.1. 94 C./ 0.01 mm. Hg. Yield 59% of the theoretical.

The new ester shows on rats per os a toxicity of 25 trig/kg. LDSQ- Example 20 CH=CHP S-OH2-CN 52 grams (0.25 mol) of vinyl-thionophosphonic acid- O-ethyl-ester thiolic acid potassium salt are dissolved in 150 cc. of acetonitrile. 19 grams of chloro-acetonitrile are added with stirring at 40 C. for a further hour and then worked up in conventional manner. 30 grams of the new ester of 8.1. 86 C./ 0.01 mm. Hg are obtained. Yield 587% of the theoretical. The toxicity on rats per os is 50 rug/kg. L13

Example 21 s ooirr I claim: 1. A phosphonic acid ester of the general formula:

INC/0R1 onFoH-i XRZ wherein X stands for a chalcogen having an atomic weight from 16 to 33; R stands for an alkyl radical having up to 6 carbon atoms and R stands for a member selected from the group consisting of a lower alkyl radical substituted by a lower alkyl mercapto group, a lower alkyl radical substituted by a lower dialkyl amino group, a lower alkyl radical substituted by a phenyl mercapto group, a lower alkyl radical substituted by a halophenyl mercapto group, a lower alkyl radical substituted by a cyano group, and a lower alkyl radical substituted by a phenyl carbonyl group, nitro-substituted phenyl radical,

a lower alkyl mercapto-substituted phenyl radical and a halogen-substituted phenyl radical.

2. A compound of claim 1 wherein R is intro-substituted phenyl.

3. A compound of claim 1 wherein R is a lower alkyl mercapto-substituted phenyl radical.

4. A compound of claim 1 wherein R is a lower alkyl radical substituted by a lower alkyl mercapto group.

1 l) 5. A compound of claim 1 wherein R is a phenyl mer- 10. The compound of the following formula capto lower alkyl radical. S OCQH4 6. A compound of claim 1 wherein R is a lower alkyl C Il/ radical susbtituted by a lower dialkyl amino group. H

7. The compound of the following formula 5 0 C i1 11. The compound of the following formula oH,=oH- P oolm Q on =oH-P 8. The compound of the following formula 10 S-C aS ii 12. The compound of the following formula CHFOH-P fi/O C2115 Q' 15 oHFoH-P (3H3 S-CH2-CH2N(C:1HU2 The compound of the following formula References Cited in the file of this patent S UNITED STATES PATENTS C H H/ 20 4 2,918,488 Schrader Dec. 22, 1959 

1. A PHOSPHONIS ACID ESTER OF THE GENERAL FORMULA: 